All of lore.kernel.org
 help / color / mirror / Atom feed
From: bugzilla-daemon@bugzilla.kernel.org
To: kvm@vger.kernel.org
Subject: [Bug 201753] AMD-Vi: Unable to write to IOMMU perf counter
Date: Thu, 25 Mar 2021 21:51:54 +0000	[thread overview]
Message-ID: <bug-201753-28872-3vaqHzRI1Y@https.bugzilla.kernel.org/> (raw)
In-Reply-To: <bug-201753-28872@https.bugzilla.kernel.org/>

https://bugzilla.kernel.org/show_bug.cgi?id=201753

--- Comment #33 from David Coe (david.coe@live.co.uk) ---
Good evening all!

Herewith a summary of our various results, including my latest for the Ryzen 7
4700U (Acer Swift 3).

20 msec wait with logged retrys

Ryzen     Kernel            Cold    Warm

4700U   5.11.0-11            6      1
3500U   5.11.7               5      6
2500U   5.8.0-45                    5
        5.12.0 RC3           5    > 5
2400G   5.11.0-11            6      6
        5.8.0-45             5      6
2200G       ?                     >10

Two points are clear:

1. there are differences between cold and warm boot, mostly marginal but marked
and very consistent with my 4700U.

2. the choice of 5 as the maximum retry number is (sorry, Suravee) unfortunate.
Mostly, it guarantees that all our Ryzens just fail the IOMMU write test!

Paul's experiences with the 2200G are the exception and I can appreciate his
unease about just increasing the number of retrys. I'm sure he, Suravee, Alex
and the AMD engineers will find an elegant solution to the problem :-).

In the meantime, could you formally patch-the-patch, Suravee? I'll pass on the
above data to Alex Hung, our "cherry-picker" at Ubuntu.

Best regards

David

-- 
You may reply to this email to add a comment.

You are receiving this mail because:
You are watching the assignee of the bug.

  parent reply	other threads:[~2021-03-25 21:52 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <bug-201753-28872@https.bugzilla.kernel.org/>
2020-03-27 20:58 ` [Bug 201753] AMD-Vi: Unable to write to IOMMU perf counter bugzilla-daemon
2020-03-27 21:06 ` bugzilla-daemon
2021-02-02  1:33 ` bugzilla-daemon
2021-02-06  3:42 ` bugzilla-daemon
2021-02-06  4:01 ` bugzilla-daemon
2021-02-10 19:52 ` bugzilla-daemon
2021-02-10 19:54 ` bugzilla-daemon
2021-02-11 18:03 ` bugzilla-daemon
2021-02-24 20:32 ` bugzilla-daemon
2021-02-25 17:54 ` bugzilla-daemon
2021-02-26 11:58 ` bugzilla-daemon
2021-02-26 13:28 ` bugzilla-daemon
2021-02-26 21:17 ` bugzilla-daemon
2021-02-27 15:21 ` bugzilla-daemon
2021-02-28 20:04 ` bugzilla-daemon
2021-03-03 18:24 ` bugzilla-daemon
2021-03-05 10:26 ` bugzilla-daemon
2021-03-08 10:46 ` bugzilla-daemon
2021-03-15 22:00 ` bugzilla-daemon
2021-03-16 11:14 ` bugzilla-daemon
2021-03-17 10:32 ` bugzilla-daemon
2021-03-18  1:22 ` bugzilla-daemon
2021-03-18  8:41 ` bugzilla-daemon
2021-03-18 16:41 ` bugzilla-daemon
2021-03-19  9:13 ` bugzilla-daemon
2021-03-19  9:56 ` bugzilla-daemon
2021-03-19 16:37 ` bugzilla-daemon
2021-03-19 20:43 ` bugzilla-daemon
2021-03-25 21:51 ` bugzilla-daemon [this message]
2021-08-26  8:42 ` bugzilla-daemon
2021-08-26  8:43 ` bugzilla-daemon
2021-10-01 19:54 ` bugzilla-daemon

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=bug-201753-28872-3vaqHzRI1Y@https.bugzilla.kernel.org/ \
    --to=bugzilla-daemon@bugzilla.kernel.org \
    --cc=kvm@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.